The purpose of this study was to determine whether HIV protease inhibitors affected the ability of the body to eliminate several drugs used to treat elevated cholesterol concentrations, since elevated cholesterol is one of the side effects of HIV treatment. The study was carried out in healthy volunteers who received a "statin" drug for several days, followed by a protease inhibitor (PI) combination, ritonavir and saquinavir, and finally both statin and PIs given together. Blood was taken to measure drug concentrations of the statin while administered alone and then again while given with the PIs. Three different statins were investigated: simvastatin, pravastatin and atorvastatin. This was a multicenter study done at several sites throughout the US, including Stanford.